1. Field of the Invention
The present invention relates to medical retrieval or electro-cutting devices, and more particularly to a medical retrieval or electro-cutting device including a rotatable end effector.
2. State of the Art
Medical retrieval or electro-cutting devices are used for a number of purposes within the body cavity. For example, a medical retrieval device in the form of a snare instrument is used for the endoscopic removal of hypertrophic tissue growths or polyps within a body cavity. Snare instruments generally include an elongated tubular member, such as a catheter sheath, a wire or shaft extending through the tubular member, and an elastic wire (e.g., stainless steel or Nitinol) forming a loop movable distally and proximally within the tubular member. The loop can be opened by moving the loop beyond the distal end of the tubular member and closed by retraction into the tubular member. Loop opening and closing is effected by movement of the shaft relative to the tubular member. A handle is provided at the proximal end of the instrument to facilitate this movement.
With the loop of the snare instrument in a retracted position, the distal end of the instrument is inserted through an endoscope into the gastrointestinal tract and moved toward a polyp or other tissue growth which is identified for removal from the wall of the tract. The handle of the instrument is then operated to expand the loop of the snare and an attempt is made to maneuver the loop to surround the polyp. If successful, the loop is then constricted about the polyp to excise it.
It will be appreciated that manipulation of the loop of the snare instrument about the polyp is a difficult, and sometimes unattainable, task. The expanded snare loop often lies in a plane which is not conducive for maneuvering about the target polyp. Therefore, the desired polyp retrieval often requires extensive effort, including attempts to rotate the catheter sheath to orientate the snare loop about the polyp. Rotation of the catheter sheath, however, often moves the snare loop out of position or causes detrimental whipping of the snare loop during the procedure.
The objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention comprises a medical instrument including a sleeve having a proximal end and a distal end, a shaft at least partially received in the sleeve and including a proximal end and a distal end, an end effector connected to the shaft distal end, and a shaft portion having a discontinuous outer surface profile, a handle assembly attached to the proximal end of the sleeve and the proximal end of the shaft, the handle assembly capable of controlling at least a linear movement of the shaft, and a torque transmitter element fixedly located within the sleeve and having an opening extending therethrough for receiving the shaft portion, a surface of the opening having a discontinuous profile for mating with the discontinuous profile of the shaft portion so that a linear movement of the shaft causes a rotational motion of the end effector.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention further comprises a medical instrument including a sleeve having a proximal end and a distal end, a shaft formed of at least a first and second shaft segments, the shaft at least partially received in the sleeve and including a proximal end and a distal end, an end effector connected to the shaft distal end, and a shaft portion having a discontinuous outer surface profile, a handle assembly attached to the proximal end of the sleeve and the proximal end of the shaft, the handle assembly capable of controlling at least a linear movement of the shaft, a torque transmitter element fixedly located within the sleeve and having an opening extending therethrough for receiving the shaft portion, a surface of the opening having a discontinuous profile for mating with the discontinuous profile of the shaft portion so that a linear movement of the shaft causes a rotational motion of the end effector, and a pivot connector located within the sleeve and proximal to the torque transmitter element, the pivot connector including a housing for receiving a distal end of a first shaft segment and a proximal end of the second shaft segment, the housing substantially restricting relative linear movement of the first and second shaft segments while allowing unrestricted relative rotational movement of the first and second shaft segments.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention further comprises a medical instrument including a sleeve having a proximal end and a distal end, a shaft formed of at least a first and second shaft segments, the shaft at least partially received in the sleeve and including a proximal end and a distal end, an end effector connected to the shaft distal end, and a shaft portion having a discontinuous outer surface profile, a handle assembly attached to the proximal end of the sleeve and the proximal end of the shaft, the handle assembly capable of controlling at least a linear movement of the shaft, a torque transmitter element fixedly located within the sleeve and having an opening extending therethrough for receiving the shaft portion, a surface of the opening having a discontinuous profile for mating with the discontinuous profile of the shaft portion so that a linear movement of the shaft causes a rotational motion of the end effector, and a clutch assembly located within the sleeve and distal of the torque transmitter element, the clutch assembly including a clutch housing for receiving a distal end of the first shaft segment and a proximal end of the second shaft segment, the housing restricting controlled rotational movement of the end effector to only one rotational direction.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention further comprises a method of positioning an end effector of a medical instrument at a desired location comprising the steps of positioning a sleeve within a patient the desired location, the sleeve including therein a shaft having the end effector connected to a distal end thereof; and moving a portion of the shaft in a linear direction through a torque transmitter element to cause rotation of the end effector to a desired rotational position.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.